There is an ink jet printer type which prints bar codes (or the like) on sheets of paper such as postal matters (e.g., letters, postcards, parcels, or the like), with the bar codes providing destination information or the like. This type of ink jet printer detects conveyed postal matters by using a printing timing sensor, and ejects ink to the postal matters from a printer head so as to perform printing on the postal matters based on the detection.
According to the ink jet printer in the related art, however, there arises a problem in that the ink reaching the postal matters splashes against the postal matters and contaminates the surroundings with the splashing of the ink.
Moreover, the ink splashed against the postal matters adheres to the printing timing sensor, which can cause a problem of erroneous ejection of ink from the printer head.